I have added to the workbook created by S M C to add views of regions. Now, there are graphs for:
  • World
    Africa/Middle East
    Asia/Middle East
    Central/South America
    Europe
    North America
    Oceana
    USA
    USA-Midwest
    USA-Northeast
    USA-Mid Atlantic
    USA-Southeast
    USA-South
    USA-Southwest
    USA-Northwest
    USA-Central
    Germany
    U.K.

I have taken out some of the duplicate graphs, but you can add those back from the original file by copying them in. I have changed a couple of sheet labels in the macro, but the rest is the same way as S M C wrote it.
As far as upgrading it from here goes, I think making additional graphs for more countries/regions would be good, and creating a macro that can handle large numbers of locations. The plot currently has a maximum of 256 points, so finding a way to add more would be good as well (maybe overlaying multiple plots).

Here is the file:
https://docs.google.com/open?id=0B9i...UJocGdGaDRJakE